Self-aligning belt idler



May 7, 1946. G. F. DODGE 2,399,913

SELF-ALIGNING BELT IDLER Filed Dec. 7, 1945 HTT Y GGEDON F DODGE,

Patented May 7, 1946 SELF-ALIGNING BELT IDLER Y Gordon F. Dodge, Columbus,` Ghia, assigner, by

assignments, to The JeRrey Manufacturing Company, a corporation of Ohio Application December 7, 1943, Serial No. 513,310

iClaim.

dlThis invention relates to a self-aligning belt i er.

An object of the invention, therefore, is to provide an improved self-aligning belt idler.

A further object of the invention is to provide a very eflicient self-aligning belt idler which includes a, swingable idler roller supporting frame which swings on an inclined axis which passes through, or substantially through, the center of gravity of the swingable frame and those partsV which are carried by it and which includes yindependently rollable idlers.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claim.

In the accompanying drawing,

Fig. 1 is a transverse sectional view of -a belt conveyor including troughing and return selfaligning belt idlers incorporating my invention;

Fig. 2 is a sectional view taken-on the line 20 2-'2 of Fig. 1, looking in the direction'of the arrows;

Fig. 3 "is a sectional View taken on the line 3--3 of Fig. i, looking in the direction of the arrows;

and

Fig. 4 isa sectional view taken on the line 4-4 of Fig. 3, looking in the direction of the arrows.

Self-aligning belt idlers have been the subject of considerable investigation andnumerous proposed arrangements of parts have been made with varying degrees of complication, effectiveness and satisfactory overall results. I have discovered that none of the prior art devices provides an. efcient,. simple, yet highly effective combination of parts because in each prior artA device of which I am aware there are one or more deficiencies.

The idlers of my invention in the two embodiments, provide particular combinations of elements which make for extreme simplicity, maximum effectiveness and general overall satisfactory yoperation which is unattainable with any known prior art device.

Referring iirst to Fig. 1 of the drawing, I have shown a conveyor including a main frame I0 formed of longitudinally extending channel members Il, Il, which are interconnected at intervals by cross members, not illustrated. Ex tending laterally across the tops of the channel members Il, Il is a stationary supporting base l2 in the form of an inclined angle member having end brackets which attach it to said channel members il, Il., The angle member or base i2 forms the supporting base of a troughing type (ci. iss-m) ports the upper or load carrying run of an endless conveyor belt Il which extends between head and tail pulleys of the conveyor-which are not illustrated. The return run of the belt i4 is supported on allatself-aligning belt idler mechanism l5.

Attention is now directed to Figs. 1 and 2 of the drawing and to the troughing type self-aligning belt idler mechanism i9. In addition to the supporting base l2, said mechanism I3 includes a supporting stub shaft I6 which has a base l1 rigidly attached to the supporting base l2. Mounted upon the stub shaft I6 and supported by spaced anti-friction roller bearings i8 and i9 is a hub or casting provided with a removable enclosing cap 2i at its top and a labyrinth grease -Y seal 22 at its bottom. A grease tting 23 is provided so that the bearings I8 and I9 may be lubricated. The hub lor casting l2li is attached to the center of a swingable or pivoted frame 24 which is -in the form of an inverted angle member, the outer ends of which are bent upwardly to provide the troughing type idler assembly.

Mounted upon the frame 2| are two intermediate supporting brackets or feet 26 and two end brackets or feet 26. The four brackets or feet and 28 support three idler shafts, one of which is seen at 21 in Fig. 2 of the drawing. These three shafts support :three independently ro- 0 tatable idlers or rollers 2B, 29 and 30. The center idler or roller, cr what is sometimes called an idler roller, 29 is mounted upon a horizontal axis which passes through a vertical plane through the axis of the swingable frame 24, this axis being, of course, the axis of the shaft 21.

The inclined outer rollers or idlers l2li and 30'.

With reference to Figs. 1 and 2 of the drawing it will be seen that the axis of the stub shaft I6 and consequently the pivotal or swinging axis about which the swinging frame 2,4 pivots, lies in a vertical plane which is transverse to the normal axis of the swingable frame 24 which is also transverse to the normal axes oi rotation of the idlers 28, 29 and 30.

There is another and exceedingly important characteristic of this swingable axis about which the swingable frame 24 pivots which, of course, is the axis of the stub shaft I6, and that is, this axis while lying in the above mentioned vertical plane also preferably passes through or near the center of gravity of the assembly ofall of the v self-aligning belt idler mechanism i9 which sup- 55 swingable parts which swing with and awe carried 20. In'actual practice, this axis is preferably slightly above this center of gravity because in normal operation there is a load carried by this swingable troughing belt idlei` mechanism assembly which includes the weight of a portion ol the belt I4 and the load on it. It may be stated that the limits within which this axis may be positioned in this vertical plane are defined by a line through the axis of the shaft 2li and the roller 29 thereon and a line through the top of said horizontal roller 23. It is of particular importance to note not only the location of this axis about which the swingable frame 23 swings but it is also quite important to note that the rollers or idlers 28, 2@ and 3d are all independently rollable and are not interconnected. It is this particular combination which applicant has found to -be simple but very efficient in operation in a troughing type belt idler.

It is furthermore to be noted that considering the direction of travel of the belt ifi over the troughing idler mechanism i3, the swinging axis of said frame 24 is to the rear of the axes of the rollers 23, 29 and 30.

Considering now the structure of the return or ilat belt idler mechanism l5, the same general considerations and general construction above described fully applies though in certain details I have illustrated different construction. The at belt idler mechanism I includes a stationary supporting base 3| in the `form of an inverted angle member which is provided at its ends with hangers 32, 32 by which it is connected to the bottoms of the channel members il, Il. Adjacent its center, the base 3i is provided with a pivot'socket or casting 33 which has a base 34 bolted or otherwise attached to the supporting base 3|. The pivot socket or casting 33 carries an upwardly inclined' pivot pin 3E which' is journaled in said socket for pivotal movement. At its upper end the pivot pin 35 is rigidly connected to a swingable or pivoted frame 36 whichis a composite structure formed of a hollow tube 3l at the center of which is attached the pin 35 and through which there extends an idler or roller supporting shaft 33 which is rigidly butremovably connected to the tube 3l through sleeves, one of which is seen at 3d and set screws. one of which is seen at dii. A drip shield di is provided at the center of the swingable frame 36 and extends over the pivot socket 33. At opposite ends there are idlers or rollers d2 and 33 which are mounted on the slat 38 by anti-friction bearings, one of which is seen at 44. It is of particular importance to note that the shaft 38 is a dead shaft and npt a live shaft, that is, it does not rotate in the swingableirame 38 or tube 31. Furthermore, it is 'of importance to note that the idler rollers 42 and 43 are mounted for independent rotation because I have found that if these idler rollers are connected to rotate together, either through a shaft or are a single roller, the maximum eiiiciency of operation is not realized, as it is in my device.

From the above description it is evident that the swingable or pivoted frame 36 is rigidly attached to the pivot pin 35 and swings about the axis of said pin 35. This axis lies in a vertical plane which is transverse to the normal axis of said swingable or pivoted frame 36 and to the axes of each of the rollers 42 and 43 which coincides with the axis of said swingable or pivoted frame 36. Furthermore, in this case the pivotal axis of said frame liti, or in other words, the axis of the pivot pin 35i, passes through the axis of said swingable or pivoted frame 3G and, in common with the troughing belt idler mechanism i3, it also passes through the center of gravity of the swingable or pivoted frame 36 and those parts carried by it, including the idlers or rollers 02 and 13.

In the case of the hat type selfaligning belt idler illustrated in detail in Figs. 3 and d of the drawings, the center o gravity of the swingable frame 33 and those parts carried by it is along its own axis and the presence of the belt it and the load on its in nowise changes the location of the center of gravity. In other words, in this regard the at belt idler mechanism of l5 is a special case of the troughing belt idler mechanism i3. In common with the troughing belt idler mechanism I3, the at belt idler mechanism I5 is also one in which considering the direction of travel of the belt Hl over the troughing idler mechanism I3 the swinging axis of the frame'Zl is to the rear of the axes of the rollers 2li, 29 and 30.

It may further be pointed out that to provide for lubrication of the pivot pin 35 in the socket 33, the bottom end of the socket 33 is closed by a plug 45 provided with a grease tting ri.

Operation of the belt idler mechanisms i3 and i5 is entirely automatic, being induced by unbalancing of loads about the inclined pivots. A belt running to one side depresses the heavy side, but dueto the inclined pivot a downward movement must be accompanied by a, swinging movement and this swingingmovement is in the correct dlrection to deect the belt back to a central position.

It should bey noted particularly that with this construction the tendency for correction is immediate upon development of any unbalance in the supported load and does not wait upon a. sutilcient deviation from alignment for the edges of the belt to actuate some auxiliary mechanical device for swinging the idler. Further, not depending upon such auxiliary mechanisms, these are eliminated along With their frequent damaging of the edges of the belt and displacement of occasional overhanging lumps of the load being carried.

It is to be understood that in e. complete conveyor there will be at desired intervals trcughing idler rollers I3 either with or without return idler rollers i5, or vice versa, and normally there will be plain troughing and belt supporting idlers bctween the self-aligning idlers.

It is further to be noted that the idler mechanlsm I5 is not limited to return belt operation. For example, there are many cases in which the upper or working run is a flat belt and in such cases the flat belt mechanism may be employed. It is further obvious that the idler mechanisms I3 and i5 may be employed each without the other in any case where it is desired.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by vthe claim hereto appended and I wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

s,seo,o1s

porting 'said idler rollers for free rotation there A belt idler assembly adapted to support and train a moving belt including a swinzable tubular frame member having a pivot shaft extending at right angles to its longitudinal axis, a sleeve member associated with each end oi said frame member, a shaft extending through said frame member along its longitudinal axis through said sleeve members and carried by the latter, means securing said shaft against movement relative to said on, a stationary supporting base for said frame member in the form of an inverted angle member having hangar means adjacent its ends. and an upwardly inclined pivot socket having a mount adapted to be received by said inverted angle member. said base supporting the pivot shaft of said tubular frame in an inclined position whereby said frame may pivot on its pivot shaft to train members, an idler roller adjacent each of said 10 abelt carriedby the idler rollers.

sleeve members, anti-friction bearing means associated with each of said sleeve members sup- GORDON F. DODGE. 

